First Online: 28 July 2009Received: 16 March 2009Revised: 20 May 2009Accepted: 11 June 2009

Abstract

BackgroundPhase imaging derived from equilibrium radionuclide angiography presents the ventricular contraction sequence. It has been widely but only indirectly correlated with the sequence of electrical myocardial activation.

ObjectivesWe sought to determine the specific relationship between the sequence of phase progression and the sequence of myocardial activation, contraction and conduction, in order to document a noninvasive method that could monitor both.

MethodsIn 7 normal and 9 infarcted dogs, the sequence of phase angle was correlated with the epicardial activation map in 126 episodes of sinus rhythm and pacing from three ventricular sites.

ResultsIn each episode, the site of earliest phase angle was identical to the focus of initial epicardial activation. Similarly, the serial contraction pattern by phase image analysis matched the electrical epicardial activation sequence completely or demonstrated good agreement in approximately 85% of pacing episodes, without differences between normal or infarct groups.

ConclusionsA noninvasive method to accurately determine the sequence of contraction may serve as a surrogate for the associated electrical activation sequence or be applied to identify their differences.

KeywordsContraction excitation equilibrium radionuclide angiograms phase image analysis The authors had full access to the data and take full responsibility for its integrity. All authors have read and agree to the article as written.

The manuscript is from UCSF not from Alta Bates or Evera. The latter is where the respective people currently work.